The present invention relates to a wireless data transmitting and receiving system, a server device and a server device controlling method, the system having the server device wirelessly connected to a plurality of wirelessly networked clients, the server device wirelessly supplying the clients with externally acquired reproduced data as requested by the clients.
Recent years have seen the development and implementation of digital satellite broadcasting in addition to conventional analog terrestrial TV broadcasts and analog satellite broadcasts using broadcasting and communication satellites. In a digital satellite broadcast, a single broadcast wave typically has data representative of numerous programs multiplexed therein on a time division basis. In other words, one broadcast wave is used to broadcast concurrently a large number of programs.
To receive and enjoy any of the programs offered by digital satellite broadcasting involves the use of a digital satellite broadcast receiver such as IRD (integrated receiver/decoder). When a broadcast wave from a target satellite is received, EPG (electronic programming guide) information contained in the wave is referenced and a desired broadcast program is selected accordingly for enjoyment.
When a single broadcast wave offers many programs simultaneously, there will be a growing number of cases in which family members of each household may wish to view different programs individually. The situation requires that broadcast programs be watched not only in the family's shared space such as the living room but also in individual rooms as desired.
The requirement is typically met by setting up a satellite broadcast receiver together with a monitor unit or a television set in each room, plus a VTR (video tape recorder) where necessary. The setup is designed to let the members in different rooms receive selectively the desired broadcast programs for individual enjoyment.
The setup above, however, has a number of disadvantages. Installing a plurality of satellite broadcast receivers in each household can be costly. To equip individual rooms with the satellite broadcast receiver requires leading an antenna cable into all rooms involved from a satellite broadcast receiving antenna, which can be a troublesome chore.
With a plurality of satellite broadcast receivers set up in the household, they obviously receive the same satellite broadcast signal. A user in each room operates his or her receiver to tune in selectively to a desired program. This amounts to a waste of resources, with the multiple satellite broadcast receivers receiving the same program signal that includes programs not selected by anyone. The setup can also lead to increased power consumption in the household.
These shortcomings notwithstanding, it is impossible for the receiver side (i.e., viewers side) directly to control the program transmitter side (i.e., broadcasting station side) in a manner requesting the latter to send only desired programs. Even if an individual receiver (i.e., viewer side) succeeds in requesting the transmitter side (i.e., broadcasting station side) to transmit a specific program, the transmitter side cannot possibly cope with such requests coming simultaneously from a large number of receivers.
One solution to the above problems is to build what is known as a home network system by wirelessly connecting a satellite broadcast receiver with a plurality of monitor units. In this system, the satellite broadcast receiver corresponds to a wireless server device and each monitor unit represents a wireless client device.
The advantage of getting a plurality of wireless client devices (i.e., monitor units) to share a single wireless server (satellite broadcast receiver) is apparently twofold: a single receiver replacing the conventionally required multiple receivers, and the absence of antenna cables snaking from one room to the next. The solution is supposed to make it easier to enjoy TV programs anywhere in the household.
The advantage above may well be offset by a number of deficiencies. Wireless transmission of broadcast programs from a satellite broadcast receiver in a given household to its monitor sets can spill out to and be tapped by monitor units in neighboring households.
Since many digital satellite broadcast channels are chargeable, receiving spillover transmissions from a satellite broadcast receiver next door is equivalent to piracy. With due fees for the reception left unpaid, copyright holders' interests are infringed on. From the viewpoint of family members in possession of the satellite broadcast receiver, their privacy is violated when their preferences in the selection of broadcast programs become known to their neighbors.
In addition to the problem of potential encroachment on the family' privacy by its neighbors, individual family members' privacy can also be violated by other members within the same home network system if it is easy for any one member in one room to know the program any other member is watching in another room. It is preferable that each family member's privacy be protected as well even within the same home network.
Furthermore, installing a home network system, it should be noted, satisfies users only if the system is appreciably easier to operate and consumes much less power than the conventional setup where a plurality of satellite broadcast receivers are connected to monitor units and/or VTRs.